I don't know anything about amphotoworld. I saw their ad in a magazine. I don't know if they're just blowing smoke, or whether items are gray market, or whether items are even available.
They have *ist D's listed for $739 and DS's listed for $519.
http://www.amphotoworld.com/results.asp?qu=&om=&manuf=Pentax&searchcat=21&sort=4
Again this is not an endorsement.
Tom C.
They are one of those NYC mail order stores that gives NYC a bad name.
Resellerratings.com rating
http://www.resellerratings.com/seller1988.html
0.60 on a 0-10 scale
Caveat emptor
Butch
